Can I make a software inside Blender?
Looks like you'd need to experiment.
Pick a small task, give yourself a week to solve it, reflect, iterate (cf. PDIA, Cynefin-complex, Fail faster).

Here's some ideas for you to test:


Making a different software out of Blender might require changing the source code, so try to build Blender from source. See if the build cycle is fast enough.
You'll likely need to remove the unnecesary tools from the user interface, so see if you can.
You'll likely need to add new tools or behaviours to the user interface, so see if you can.